%0 Journal Article
%J Physical Review Letters
%D 2013
%T Spinor dynamics in an antiferromagnetic spin-1 thermal Bose gas
%A Hyewon K. Pechkis
%A Jonathan P. Wrubel
%A Arne Schwettmann
%A Paul F. Griffin
%A Ryan Barnett
%A Eite Tiesinga
%A Paul D. Lett
%X We present experimental observations of coherent spin-population oscillations in a cold thermal, Bose gas of spin-1 sodium-23 atoms. The population oscillations in a multi-spatial-mode thermal gas have the same behavior as those observed in a single-spatial-mode antiferromagnetic spinor Bose Einstein condensate. We demonstrate this by showing that the two situations are described by the same dynamical equations, with a factor of two change in the spin-dependent interaction coefficient, which results from the change to particles with distinguishable momentum states in the thermal gas. We compare this theory to the measured spin population evolution after times up to a few hundreds of ms, finding quantitative agreement with the amplitude and period. We also measure the damping time of the oscillations as a function of magnetic field.
%B Physical Review Letters
%V 111
%8 2013/7/9
%G eng
%U http://arxiv.org/abs/1306.4255v1
%N 2
%! Phys. Rev. Lett.
%R 10.1103/PhysRevLett.111.025301
%0 Journal Article
%J Physical Review Letters
%D 2009
%T Number Fluctuations and Energy Dissipation in Sodium Spinor Condensates
%A Yingmei Liu
%A Eduardo Gomez
%A Stephen E. Maxwell
%A Lincoln D. Turner
%A Eite Tiesinga
%A Paul D. Lett
%X We characterize fluctuations in atom number and spin populations in F=1 sodium spinor condensates. We find that the fluctuations enable a quantitative measure of energy dissipation in the condensate. The time evolution of the population fluctuations shows a maximum. We interpret this as evidence of a dissipation-driven separatrix crossing in phase space. For a given initial state, the critical time to the separatrix crossing is found to depend exponentially on the magnetic field and linearly on condensate density. This crossing is confirmed by tracking the energy of the spinor condensate as well as by Faraday rotation spectroscopy. We also introduce a phenomenological model that describes the observed dissipation with a single coefficient.
%B Physical Review Letters
%V 102
%8 2009/6/5
%G eng
%U http://arxiv.org/abs/0906.2110v1
%N 22
%! Phys. Rev. Lett.
%R 10.1103/PhysRevLett.102.225301